The present invention relates generally to improvements in display area illuminating structures and it relates more particularly to an improved system for illuminating by exterior natural or artificial ambient light substantially vertical display areas such as paintings, prints and the like.
In art museums, galleries and other exhibition areas the exhibits in the form of paintings and the like are conventionally hung on vertical walls or panels and illuminated by artificial illumination or by natural ambient exterior light traversing light transmitting ceiling or windows of the light exhibition area. Where natural exterior ambient light is employed by conventional systems, the illumination of the display area and the surrounding areas affords an inferior viewing of the display area. Thus, showing in FIG. 1 of the drawing is a painting exhibition wall 10 which is typical of the prior art and includes a floor 11, a skylight ceiling 12 allowing the entry of light through the full area of the ceiling, and a vertical end wall 13 supporting a display area defining painting 14 which lies in an approximate vertical plane and is about at eye level. It is clear from the illustration that both near and far observers A and B view the painting under very poor viewing conditions. The near observer A views the painting 14 under high glare conditions due to the specular reflection by the painting 14 of the skylight to the observer, whereas the far observer B viewing the painting is exposed to direct light from the skylight. Therefore, both in the cases of near and far observers, the viewing of the painting is accompanied by high direct or reflected glare which radically reduces the contrast of the observed picture, washing out and masking fine detail. Further glare is encountered by light traversing the skylight and reflecting from other surfaces such as floor 11 and wall 13. Accordingly, the illumination of display areas by ambient exterior light by the conventional systems possesses numerous drawbacks and disadvantages.